Goods transport vehicles are known of the type comprising a deck which is provided at its front end with a pivot and with a retractable group or "landing leg", and at its rear end with a retractable road axle assembly, thus enabling the deck to be used both as a semi-trailer on the road and also to be placed on axles or bogies fitted with flanged wheels suitable for running on rails, thereby enabling the vehicle to be transformed into a rail vehicle and coupled in a train.
French Pat. No. 1 368 963 (P. Perrot) describes semi-trailers of this type which are capable of being placed on two removeable load-carrying bogies, and in which each bogie is fitted with an auxiliary chassis carrying a standard rail coupling system.
The deck of the semi-trailer and the front and rear auxiliary chassis are assembled together by means of lateral bolts. In addition, the pivot of the semi-trailer participates in assembling the semi-trailer to the front auxiliary chassis.
French Pat. No. FR 78/18.875 (publication 2.395.852) (The Bi-Modal Corporation) describes dual-purpose rail/road semi-trailers, each of which includes, at its rear end, a retractable road axle assembly and a rail bogie which is also retractable, and which remains fixed to the semi-trailer. The chassis of the semi-trailer is supported by via pneumatic springs both when using the road axle assembly and when using the rail axle assembly.
European patent application No. EP-A-0 112 778 (P. Perrot) describes transformable vehicles usable for road or rail transport, each comprising a load-carrying deck fitted with longitudinal frame members having an omega-shaped cross-section. The deck is fitted with a retractable road axle assembly and it is suitable for being placed on two removeable rail bogies each including an intermediate chassis carrying rail coupling devices.
Each intermediate chassis includes vertically movable blocks fitted with wheels over which a plate forming a portion of the deck can run, thereby enabling the deck to be displaced transversely for centering purposes. The intermediate chassis is fitted with pivoting hooks which hook onto the side edges of the deck in order to lock the deck to the bogies.
In addition, the deck includes transverse wheels which bear against the intermediate chassis, thereby allowing the deck to slide in translation over the intermediate chassis in the event of a shock.
French Pat. No. FR 1 598 994 (P. Perrot) describes rail/road semi-trailers, each of which include a chassis fitted at its front end with a prop, and at its rear end with a road axle assembly that can be raised by means of a ram, which chassis can be placed on and bolted to two rail bogies each of which is fitted with an auxiliary chassis carrying coupling members. The bolts operate transversely.
French Pat. No. FR 1 358 504 (C. Douheret) describes semi-trailers including rear axles carrying rail wheels onto which road wheels can be fitted, and having front portions suitable for placing on a rail front axle assembly via the coupling pivot of the semi-trailer.
The chassis and the rail front axle assembly are locked together by means of pins.
Publication No. EP-A-0 143 614 (Trailer Train Limited) describes semi-trailers which are fitted with raisable rail axle assemblies.
The rear end of each semi-trailer includes a box section enabling the chassis to be placed on a rail bogie and enabling it to be bolted thereto.
The front end of the chassis carries a draw-bar which enables it to be pivotally coupled to the rear end of the preceding rail vehicle.
The present invention relates not only to dual-purpose rail/road vehicles of the type described in the above documents which may be used either as road semi-trailers or else as articulated or non-articulated rail vehicles, but also to decks which are incorporated in multi-mode goods transport systems, e.g. containers suitable for transport by ship, by air, or on road vehicles, and which may be transformed into articulated or non-articulated rail vehicles.
For reasons of simplicity, the term "container" is used below in a general sense to designate not only decks which are fitted with a closed box structure, but also decks for carrying tanks or hoppers for transporting powder materials, or bare decks, or decks fitted with side boards.
Multi-mode goods transport system capable of being transformed into rail vehicles are very practical since they enable a consignment of goods to be transported both by rail and then by some other mode of transport, e.g. road, ship, or by air, without having to trans-ship the goods individually.
Multi-mode transport systems capable of being transformed into rail vehicles present practical implementation problems where the deck is placed on rail bogies. It is necessary for the deck to center itself automatically relative to the bogies without requiring large forces to be applied. It is also necessary for the mechanical connection between the deck of the system and the intermediate chassis of the bogie to be capable of withstanding large traction and compression forces whenever the deck is used as a rail vehicle incorporated in a train.
An object of the present invention is to provide goods transport systems capable of being transformed into rail vehicles and including improved means for centering and the deck of the transport system relative to the intermediate chassis fitted to rail bogies, and for mechanically connecting it thereto.
Another object of the present invention is to provide goods transport systems capable of being transformed both into normal rail vehicles which are coupled to one another by couplings, and into articulated rail vehicles, thereby enabling a single deck to be incorporated in a multiple unit of articulated vehicles and then in a normal train.